Contact printer



Sept 20, 1955 H. R. GULLlxsoN ETAL 2,718,181

CONTACT PRINTER Filed Sept. 14, 1951 2 Sheets-Sheet l hw 1 w Sept. 20,1955 H. R, GULLlxsoN ErAL 2,718,181

CONTACT PRINTER Filed Sept. 14, 1951 2 Sheets-Sheet 2 United StatesPatent O CONTACT PRINTER Harold R. Gullixson, Evanston, and Ored L.Smith, Western Springs, Ill., assignors to Ditto, Incorporated, Chicago,Ill., a corporation of West Virginia Application September 14, 1951,Serial No. 246,669

Claims. (Cl. 95-73) This invention relates to contact printers and likedevices for making photographic prints from negatives; in particular, itrelates to an improvement in the type of contact printer shown in theco-pending application of Harold R. Gullixson, Serial No. 246,668, filedconcurrently herewith.

In that application, there is disclosed a printer embodying a pneumaticcushion. The pneumatic cushion serves to hold a print and a negative, ora master sheet and a negative, in close contact with each other bypressing them against a transparent print supporting surface, such as asheet of glass.

In making such prints, it is often desired to expose one portion of theprint and negative for a longer period of time than other portions inorder to bring out high lights or otherwise to improve the quality ofthe print or master sheet. This can be accomplished by masking out aportion of the negative. To do this the exposure period is divided intotwo sub-periods, and the mask is placed over the negative during theinterval between these two subperiods.

To avoid disturbing the relationship between the print and the negative,which would occur if the pneumatic cushion were released, the mask canbe secured to the opposite or underside of the transparent printsupporting surface. However, in certain types of printers, includingthat shown in the aforesaid pending application, the underside of theglass sheet is not readily accessible. The glass sheet is located in thebase of the printer, and is disposed above the light source. Thishorizontal disposition of the glass sheet, together with the fact thatit is enclosed within a base, makes the undersurface of the glass sheetcomparatively inaccessible; furthermore, if openings were provided inthe base to improve accessibility, the mask could not be positioned withany accuracy due to the arrangement of the parts.

It is an object of the present invention to provide a printer in whichthe undersurface of the transparent print supporting surface is readilyaccessible so that masking means may be applied thereto.

Another object of this invention is to provide a transparent printsupporting surface which can be moved with the cover Without destroyingthe pressure engagement between the transparent surface and thepneumatic cushion, to the end that the undersurface of the transparentprint supporting means is readily accessible.

The present invention contemplates a hinged mounting of the transparentprint supporting means on the base together with latching means forsecuring the transparent means to the cover after pressure engagementhas been obtained. Thus, when it is desired to apply masking means, thecover and the transparent means can be raised as a unit.

Still another object of the present invention is to provide means whichautomatically prevent the release of said latching means when the coveris in elevated posi-V tion. Thus, the transparent print supporting meanscannot drop away from the cover and break.

Patented Sept. 2-0, 19,55

Other objects, features and advantages will become apparent as thedescription proceeds.

With reference now to the drawings in which like reference numeralsdesignate like parts:

Fig. l is a side elevation of this invention as applied to a printer ofthe type shown and described in the aforesaid pending application, thesheathing of the base and the end plate of the cover being partiallybroken away so as to more clearly illustrate the underlying parts;

Fig. 2 is a plan sectional view taken along line 2-2 of Fig. 1;

Fig. 3 is an elevation similar to Fig. l but showing the parts inchanged position, the cover being raised;

Fig. 4 is an enlarged detail section taken along line 4-4 of Fig. 2showing the cover in operative position, with the latch engaged, and

Fig. 5 is a view similar to Fig. 4, but showing the latch disengaged.

The printer comprises a base 10 having a top surface 11. A cover 12 ishingedly mounted on the base, by means of a hinge rod 13. The latter issupported in a pair of hinge brackets 14 which are mounted on suitablestructural members, not shown. The cover includes a pair of side plates15 through which the hinge rod 13 passes. Tail strips 16 are secured tothe side plates 15 to reinforce the end plates at the pivot point and toprovide a means to which a counterbalancing spring can be anchored. Thefunction and relationship of the foregoing elements is pointed out ingreater detail in the aforesaid copending application to which referenceis hereby made.

The top surface 11 is provided with an opening which is deiined by asupporting frame 17 made of channel members. A suitable light source,not shown, is disposed beneath the frame. A transparent print supportingsurface in the form of a sheet of glass 18 is disposed in the openingand above the supporting frame 17, the frame forming a support for theglass, and a rubber gasket 19 being interposed between the two.

The glass is hingedly connected at its rear edge to the hinge rod 13 bymeans of brackets 20. The transparent print supporting means 18 includesmarginally disposed channel members which form a frame 21 which engagethe edge of the glass sheet and which provide means to which thebrackets 20 may be attached. Thus, although in its normal position, theglass 18 rests on the supporting frame 17, it may be raised with thecover so as to make accessible its undersurface.

Means are provided for engaging glass 18 by the cover so that the twomay be raised as a unit without destroying the pressure engagementbetween the glass and a pneumatic cushion 30 which is vcarried by thecover. For this purse, the frame 21 is provided with pins 22 which areengaged by latching means in the form of a bell crank lever 23. Thelatter is pivotally mounted on a bracket 24 disposed in the cover 12.The bell crank lever is provided with a hooked end 2S which is adaptedto engage the pins 22. This latching mecha-v nism, together with itsassociated parts are doubled on both sides of the cover, and since theyare identical to each other, only one will be described in detail.

An operating shaft 26 is suitably journaled in the cover and carriescams 27 which engage the bell crank levers 23 to cause the hooked endsthereof to be rotated into or out of engagement with the pins 22. Theoperating shaft, at its outer end, is bent over and provided with a knob28. A member projects from the side of the cover to provide a rest 29 onwhich the control knob may rest to maintain the cam in the Fig. 5 orunlatched position.

glass 18 will move with the cover.

In order to prevent inadvertent release of the latch when the cover isin its raised position, means are provided for locking the latch in itslatched position. This locking means comprises a blocking member 31which is pivotally mounted on bracket 24, and which is provided with adepending portion 32 which projects downwardly through the'cover andengages the top surface 11 of the base. As shown in Figs. 3 and 4, whenthe cover is down in its operative position, the locking lever iselevated, so as to permit movement of the bell crank in and out oflatched position. However, when the cover is raised, the blocking leverdrops downwardly into blocking position in which it engages the bellcrank and blocks the same, thereby locking in latched position. Thus,even though the knob 28 is manipulated when the cover is raised, thebell crank lever cannot be rotated. A spring 33 extends between the bellcrank lever 23 and the blocking lever 31 and serves the double purposeof biasing the bell crank lever into unlatched position, and of biasingthe blocking lever into locking position.

As indicated above, the cover 12 includes a pneumatic cushion which,when inated, is bowed outwardly to provide a convex surface. In normalposition, the glass 18 rests on the frame 17 in a horizontal position.As the cover is lowered into its operative position, as shown in Fig. 5,the contact between the cushion' and the glass causes the cushion to becompressed. Since the compression of the cushion requires considerableforce even though a low pressure cushion is used, clamping means areprovided to engage the cover and to draw it downwardly through the lastfew degrees of its movement into its operative position. This clampingmeans comprises a clamping bar 35 which is suitably journaled in thebase and to which is secured a pair of cranks 36. S-shaped hooks 37 arepivotally mounted on the cranks by means of pivot pins 38. Thisarrangement is doubled on both sides of the machine, only one of theclamping means being shown in Figs. l and 2. A stop plate 39, secured tothe side wall of the base, is engaged by the hook 37 and serves tomaintain the same in an upright position so that rotation of the crank,when in its down position as shown in Fig. 1, will cause the hook tomove downwardly. At this time, the hook engages a flange portion 4G ofthe cover 12, with the result that the cover is urged downwardly withconsiderable force into its operative position. The S-shape of the hookpermits the crank to be swung into an overcenter position so that thecover will remain clamped in its operative position.

The operation of the clamping means is described in greater detail inthe aforesaid co-pending application. It will be observed that a spring41 extends between the tail of the clamp and the crank which serves tourge the hook forwardly into engagement with the flange portion and intoengagement with the stop plate 39. A pin 42 limits the counterclockwisemovement of the hook with respect to the crank so that when the clampingshaft 35 is rotated 180 in the clockwise direction from the Fig. lposition, the hook will be rotated backwardly and downwardly to a pointwhere it is retracted within the base.

To summarize the operation, a print and negative, after being aligned,are rst laid on the glass 18, the cover at this time being raised. Thenthe cover is lowered and the clamping shaft 35 is rotated so as toengage the cover and draw it down into its operative position, againstthe pressure of the cushion. Now the glass and the cushion are inpressure engagement with each other.

Assuming that it is desired to expose one portion of the print for ashort period and the other portion for a longer period, the timer of theprint is set for the short period, and the entire print is automaticallyexposed for this short period. Then, the control knob 28 is rotated inthe counterclockwise direction from its Fig. 5 position to the Fig. 4position which causes bell crank leversv 23 to engage the pins 22,thereby latching the glass to the cover. Then the clamping shaft 35 isrotated to release and retract the hooks 37. However, this does notrelease the pressure engagement between the cushion and the glass due tothe latched condition of these parts.

The cover may now be elevated into its Fig. 3 position. The elevation ofthe cover automatically causes the blocking levers 31 to engage the bellcrank levers, thereby locking the latch in their latched positions. Thisavoids inadvertent release which might cause the glass to break.

When the cover is in its raised position, masking means may be securedto the underside of the glass 18 by suitable means, such as pressuresensitive tape. Then, the cover is brought back down into its operativeposition, and the clamp shaft 35 is rotated so as to secure the cover inthis position. The timer is then set for the remainder of the exposureperiod, so that the unmasked portion of the negative and print mayreceive the desired additional exposure.

In releasing the parts, after exposure, the glass is unlatched prior torelease of the clamping means so as to achieve a gradual release of thepressure engagement.

If desired, the additional exposure of the unmasked portion can beeffected during the first exposure period, and themask removed duringthe interval prior to the second exposure period.

The disclosure of the aforementioned copending application, insofar asconsistent, is hereby incorporated in this application by reference.

Although only a preferred embodiment of our invention is shown anddescribed herein, it will be understood that various modifications andchanges may be made without departing from the spirit of our inventionas pointed out in the appended claims.

l; A contact printer comprising a hase, transparent print supportingmeans normally disposed on said base, a cover movably mounted on saidbase and having cushion means for cooperation with said transparentmeans, hinge means connecting said cover to said base, said transparentmeans being hingedly mounted on said cover so that said transparentmeans may be moved with said cover away from said base, clamping meansfor drawing said cover into operative position against said base so thatsaid cushion means is forced into and maintained in pressure engagementwith said transparent means, and latching means mounted on said coverfor engaging said transparent means when said cover is clamped in itsoperative position so as to maintain said transparent means and saidcushion in pressure engagement with each other after said clamping meansis released to permit said cover and transparent means to be removedfrom said base without destroying said pressure engagement.

2. A contact printer comprising a base having an opening formed in itstop surface, transparent print supporting means normally disposed insaid opening, pivot means mounted on said base, a cover hingedly mountedon said pivot means and having cushion means for cooperation with saidtransparent means, clamping means for drawing said cover into operativeposition against said base so that said cushion means may be forced intoand maintained in pressure engagement with said transparent means, saidtransparent means being hingedly mounted on said pivot means formovement with said cover into a raised position, and latching meansmounted on said cover for engaging said transparent means when saidcover is clamped in its operative position so as to maintain saidtransparent means and said cushion in pressure engagement wtih eachother after said clamping means is Y released to permit said cover andtransparent means to be raised as a unit.

3. A contact printer as claimed in claim 2 having means for locking saidlatching means in latched position when said cover is raised.

4. A contact printer as claimed in claim 2 in which said latching meanscomprises a latching member mounted in said cover and movable between alatched and a released position, and locking means engaging said pivotedlatching member when it is in its latched position to maintain the samein said latched position.

5. A contact printer as claimed in claim 4 in which said locking meanscomprises a blocking member mounted for engagement with said latchingmember and movable between an operative position and an inoperativeposition, said blocking member including a portion projecting throughsaid cover into engagement with said base whereby said locking member ismaintained in its inoperative position by the engagement of saidprojecting portion with said base when said cover is in its operativeposition, said blocking member being movable into its operative positionas movement of said cover away from said base permits said projectingportion to be projected through said cover to a greater extent.

References Cited in the le of this patent UNITED STATES PATENTS 966,499Ware Aug. 9, 1910 2,494,282 Campbell Jan. 10, 1950

